Rack-mounted computer systems offer high computer density for situations utilizing multiple computer systems. In some cases, each rack-mounted computer system has one or more switching power supplies to convert alternating current (AC) power to direct current (DC) power for use. In other cases, the rack mounted computer systems may be “blade servers,” where each blade server selectively plugs into a rack-mounted enclosure, and the blade servers within the enclosure are provide DC power from switching power supplies associated with the enclosure as a whole, rather than with particular blade servers.
Regardless of whether computer systems are rack mounted themselves, or blade servers within a rack-mounted enclosure, for high reliability each rack-mounted computer system and/or enclosure for blade servers may have redundant power supplies couple to different sources of AC power. In the event one source of power fails (e.g., a circuit breaker trips), the computer systems may still remain operational based on the alternate source of power. However, ensuring that redundant power supplies are indeed coupled to intended sources of power is sometimes difficult, particularly given the number of power cables and data cables populating the back of a rack comprising plurality of rack-mounted computer system. In many cases, a power cable routing error may not be discovered until loss of an AC source results in catastrophic failure.